Menu

Security Blog

Repurposing Data…or, “You’re Going To Do WHAT?”

By Patrick Madden

Boston.com published an AP story that Google is implementing an opt-in beta test to include users’ email in search results. In other words, when a user is logged in at Gmail, performing a plain old Google search will turn up emails in addition to web pages. Privacy concerns have been flagged and noted, and the existence of matching emails will be presented using a collapsed control off to the side of the main results. But will this really do the job? Google searches are shoulder-surfed all the time, so simply disclosing even the existence of a matching email can potentially put people in hot water depending on the search terms.

Google’s beta is another instance in a disturbing trend to repurpose user data in ways that weren’t intended or anticipated when the users provided their data. As the AP article reminds us, Google had previously ventured into this territory with Google Buzz before running into legal challenges. Facebook regularly and unashamedly repurposed ancient postings, many of them ephemeral “status” updates, as users’ timelines that could be easily browsed, though it could be debated that this makes it more clear that the old posts do still exist.

In my AppSec work I regularly find “Insufficient Authorization” in sites and products I assess. These findings are generally relative to the app owner’s perspective and answer the question, “Can my user perform activities or access data in ways I don’t want?” When I look at repurposed user data, though, I see an exactly analogous situation but in the opposite direction…from the user perspective, the question becomes, “Can my service provider use my data in ways I don’t want?”

[The answer, of course, is in the terms of service wherein the providers claim rights to use and disseminate data provided to them, even if they don’t claim ownership of the actual data. Apparently, then, there’s no basis to complain about any of this, and Google, Facebook, and others will simply do what they want. That’s slightly pessimistic, but it’s not that far from what we’ve seen so far.]

When a finding of “Insufficient Authorization” appears to be the result of intended functionality, application owners are asked to review their business requirements versus the vulnerability, identify alternative means of meeting the business requirements, or reconsider the functionality altogether. On the other hand, ordinary end users are terrible at doing all of these, if they even care in the first place. Who can state their personal “business requirements” for social media and other free services, who has gone to the trouble of identifying the risks inherent in sharing personal data with third parties (and quantifying the risks? Pfft!), and who’s willing to reconsider the use of a service they’ve invested themselves in substantially, even though no payment was involved?

Repurposing of user data happens because a provider thinks they’ve found a way to make more money, and because one-sided terms of service make few concessions allowing users to control how their own data gets used. At the same time, that repurposing should never increase user risk exposure by default, at least not in my own personal utopia. Maybe we should all be looking for and flagging “Insufficient Authorization” findings from the user’s perspective. And if the Gmail feature goes live in production with no option to disable it, perhaps I can use separate email and search providers to segregate functionality and mitigate risk.